What is a GIA Tanzanite Report?

A GIA Tanzanite Report is an independent gemological document that confirms the identity and basic characteristics of a tanzanite gemstone.

To obtain one, a stone must be submitted to the Gemological Institute of America (GIA), with certification typically taking around 3–4 weeks.

GIA is one of the world’s most respected gemological authorities. While it operates laboratories globally, tanzanites submitted through their Hong Kong  office are generally sent to GIA’s laboratories in Thailand or Carlsbad (USA) for analysis.

What Does a GIA Tanzanite Report Look Like?

New Version — Issued from 2026 Onwards

From January 2026, GIA introduced a new, more visually refined report format for coloured gemstones, including tanzanite. These updated reports present the same core information but in a more modern, structured layout.

 

Classic Version — Issued Before 2026

Prior to 2026, GIA tanzanite reports followed a simpler, more traditional format. These reports included the same key details but with a more basic presentation style.

What Information Does a GIA Tanzanite Report Include?

A GIA report typically confirms:

• Carat weight
• Measurements
• Shape and cutting style 
• Species and variety (Zoisite – Tanzanite)
• Transparency - (either "transparent, semi-transparent, or opaque")
• Basic colour description (e.g. violetish blue or violet-blue)

Importantly, the report is designed to identify the gemstone, not to grade its overall quality.

Why Are Colour and Clarity Grades Not Included?

GIA does have a detailed grading system for coloured gemstones, which is taught to gemology students and widely used within the trade.

However, GIA does not apply this grading system in its official reports for tanzanite—or for most coloured stones.

This is because:

• Colour perception can vary across lighting conditions
• Coloured gemstones exist in a far broader range than diamonds
• Consistent, standardised grading is more complex - and would be hard to police world wide, across the hundreds of different types of gemstones that could be submitted to for them to grade. 

As a result, a GIA tanzanite report will only describe:

• General body colour (e.g. violetish blue or violet blue - which means a stone is blue dominant ) 
• Transparency level (transparent, semi-transparent, or opaque)

It will not specify:

• Depth of colour (pastel vs deep)
• Saturation strength
• Clarity grades or inclusions

These are critical quality factors—but they are assessed visually rather than formally graded in the report.

 

Can GIA Confirm if Tanzanite is Unheated?

No.

There is currently no reliable scientific method to determine whether a tanzanite’s colour was formed naturally underground or enhanced through heating after mining.

For this reason, GIA and other leading laboratories do not ever certify tanzanite as “unheated.”

While some research has been explored by laboratories such as Gübelin Gem Lab, no globally accepted standard has been established.

In practice:

• Most tanzanite is assumed to have been heated
• This is standard and accepted within the trade
• Unlike sapphires or rubies, heating does not reduce the value of tanzanite

Does GIA Provide Valuations or Appraisals?

No.

GIA is a research and educational institution, not a valuation body.

Their reports:

• Do not include pricing or value estimates
• Simply document the gemstone’s characteristics

If you require a valuation, this must be completed by an independent registered jewellery appraiser.

Do Tanzanite Direct Stones Come with GIA Certification?

Not all stones are GIA certified as standard, but we are increasingly offering this option -

We can arrange a GIA certificate on request for any suitable gemstone, with:

• A fee of approximately $250 USD
• A typical turnaround of 2–4 weeks

In some cases, we also hold pre-certified GIA stones which are ready for immediate dispatch.

Alternative Certification: IGI

We have also begun submitting selected stones to the International Gemological Institute (IGI).

IGI is a well-regarded international laboratory, offering:

• Faster turnaround times (typically ~10 days)
• Global presence with 31 laboratories worldwide
• Lower prices - approx $80.00 USD per cert. 

This provides a practical alternative for our clients who prefer quicker certification, and lower prices than the GIA. 

What Certification Do Tanzanite Direct Stones Include?

Every loose tanzanite gemstone from Tanzanite Direct is accompanied by:

• A full gemological report
• A guarantee of authenticity and origin

These are issued by Linda Kennedy, a GIA-trained gemologist and registered jewellery appraiser.

We also apply the GIA coloured stone grading system internally to assess:

• Colour (including blue dominance and saturation)
• Clarity
• Overall quality

This allows us to identify and offer stones in the highest tier of tanzanite quality, including those commonly called : 

• VB 6/6
• AAA+
• Heirloom grade

Final Note

Whilst the Gemological Institute of America (GIA) report is a useful tool for confirming what a gemstone is  ( especially when you are buying online ) it does not fully capture how exceptional that gemstone may be, or how beautiful you may or may not find it.

Beauty is inherently subjective, and each of us responds to different qualities.

For tanzanite, true value lies in:

• Depth of colour
• Saturation
• Brilliance
• Overall visual impact
• What makes your heart sing 

These are qualities best assessed by an experienced gemologist — and ultimately, by you seeing the stone in person. Beauty is in the eye of the beholder.